Unspecified Neurodevelopmental Disorder DSM-5 315.9 (F89)

DSM-5 Category: Neurodevelopmental Disorder

Introduction

Unspecified Neurodevelopmental Disorder (UNDD) is a DSM-5 (Diagnostic and Statistical Manual of Mental Disorders, fifth edition), diagnosis assigned to individuals who are experiencing symptoms of a neurodevelopmental disorder, but do not meet the full diagnostic criteria for one of the Neurodevelopmental disorders. The symptoms cause distress, and impair functioning in social, educational/occupational, or other major areas of functioning. The diagnosis can be assigned when the clinician decides not to specify the reason the diagnostic criteria are unmet, or if there is insufficient information available at the time of the evaluation to make a more specific diagnosis (American Psychiatric Association, 2013).

The amygdala is the brain structure most frequently implicated in NDD, which would include UNDD. A sub-cortical structure regulates our response to potentially dangerous environmental stimuli. Sensory input goes to the orbito-frontal cortex, and to the amygdala for processing on an ongoing basis. If the sensory input is deemed non-threatening, we note it and attend to the next incoming sensory stimuli. If the sensory input is recognized as a threat by the amygdala, the fight/flight/freeze response of the parasympathetic nervous system begins to activate. The amygdala acts much faster than the orbito-frontal cortex. The right frontal lobe is specifically involved with executive function- e.g., decision making- and inhibition, but processes information slowly relative to the amygdala. A threat to survival is often best dealt with urgently, which is the function of the amygdala- recognize threats, and prepare the body to engage, or withdraw, or sometimes, neuromuscular lock- e.g. - the freeze response- can be conducive to survival. Individuals with disorders along the NDD spectrum, including UNDD, have dysregulation in the amygdala, which results in inappropriate response to stimuli. An underactive amygdala can result in high-risk behavior, and inappropriate social behavior. An overactive amygdala can produce excessive anxiety and risk aversion, as well as avoidance of social interaction (Schumann, Bauman, and Amaral, 2011).

Symptoms of Unspecified Neurodevelopmental Disorder

According to the DSM-5, (American Psychiatric Association, 2013), NDD consists of a range of disorders first apparent in childhood including:

Autism spectrum disorder
CP (Cerebral palsy).
Epilepsy
Schizophrenia
Bi-polar Disorder
AD/HD (Attention Deficit/ Hyperactivity Disorder).
OCD (Obsessive Compulsive Disorder).
Disorders of communication, speech, and language.
Tic Disorders, including Tourette’s Disorder
FAS/FAE (Fetal Alcohol Syndrome/Fetal Alcohol Effects)
FXS (Fragile X Syndrome)
Rett Syndrome
William’s Syndrome
Down syndrome

There are vast quantities of symptoms for the NDD spectrum, and the symptoms of each individual disorder on the spectrum may be unique, or overlap, which can contribute to diagnostic ambiguity. There is commonality in that symptoms are manifested as disruption in physical, intellectual, emotional, behavioral, and cognitive functioning, typically first apparent in early childhood ((American Psychiatric Association, 2013; Elsevier Ltd., 2013). The debatable exceptions are Schizophrenia, and bipolar disorder. Schizophrenia does not typically manifest until the late teens-early twenties. The increasingly prominent view of Bi-polar disorder it cannot be reliably diagnosed until adulthood. However, the apparent age of emergence of these two disorders may be a result of failure to recognize early predictors. Infants can present what are termed soft neurological signs that are predictive of schizophrenia later in life. The signs include:

Lack of eye contact with their care-giver
Emotional flatness/lack of affect
Failure to meet developmental milestones for coordination

These signs are not definitive, as they can be indicative of other neurodevelopmental disorders, such as Autism Spectrum, or sensory deficits, such as hearing impairment.

Most psychological disorders are diagnosed based on the presence of symptoms, which are self-reported by the patient or their family or associates, or observed by the clinician. The symptoms of disorders indicative of UNDD are not always clearly defined, and could include:

Failure to reach expected developmental milestones for walking and speech.
Inability to interact appropriately with peers.
Poor academic performance.
Overreaction to frustration compared to peers.
Emotionally labile in comparison to peers.

Some of the disorders in this category have markers that are more objective:

Physical features associated with conditions such as Down syndrome, CP, or FSX.
Objective measures such as EEG (Electroencephalogram) confirmation of Epilepsy.
Objective measures such as the presence of the genetic markers for FSX.

Post-mortem studies also indicate there are anomalies in neuronal structures, including the soma, dendrites, axons, and at synaptic connections. An example of this is the presence of spine-like structures on the dendrites of cortical neurons in individuals with FXS (Zoghbi & Bear, 2012).

Risk Factors for Unspecified Neurodevelopmental Disorder

The DSM -5 does not specify risk factors for UNDD (American Psychiatric Association, 2013). The risk factors for UNDD will vary, as they will for NDD, depending on the exact type. Risk factors can include a multitude of genetic and environmental variables, encompassing pre-natal, peri-natal, and post-natal events, including chromosomal aberrations, or hypoxia during labor. Maternal use of ethanol during pregnancy has been identified as a major preventable contributor to NDD spectrum disorders. Including AD/HD, Developmental Coordination disorder, and MR (Mental Retardation) (Landgren, Svensson, Strömland, and Grönlund, 2010). The most obvious potential consequence of maternal use of ethanol is FAS spectrum disorders. It is noted that in the early developmental years, psychosocial factors such as the quality of adult caregiver interaction can have enduring effects, either mitigating or worsening genetic influences (Bale, Baram, Brown, Goldstein, Insel, McCarthy, Nemeroff, Reyes, Simerly, Susser, and Nestler 2010). Metabolic conditions during pregnancy, specifically maternal obesity, and two common obesity related disorders, hypertension, and diabetes, can increase risk of two specific disorders along the NDD spectrum specifically Autism spectrum disorders, and Developmental disability (Krakowiak, Walker, C.K., Baker, Ozonoff, Hansen, and Hertz-Picciotto, 2012).

Onset of Unspecified Neurodevelopmental Disorder

According to the DSM-5, UNDD, as well as the full spectrum of NDD disorders, are first apparent in early childhood (American Psychiatric Association, 2013). There are also gender differences in the onset of symptoms, e.g., boys tend to present with OCD symptoms about age five, while girls may not have symptoms until the mid-teens.

Differential Diagnosis in Unspecified Neurodevelopmental Disorder

The differential diagnosis will vary depending on the segment of the NDD spectrum that is the focus of clinical attention. The DSM -5 notes that if the clinician suspects a NDD spectrum disorder, it is important to recognize co-morbid conditions in the NDD spectrum- e.g., AD/HD with Intellectual Disability (American Psychiatric Association, 2013).

The context of the clinical presentation must be considered. The clinician must be conscientious about not pathologizing WNL (Within Normal Limits) behaviors that are better accounted for by developmental variations, or environmental stressors such as maltreatment by family or peers. The latter can produce behaviors that can be misconstrued as UNDD. A child that has been subjected to peer abuse or familial abuse may become withdrawn, excessively emotionally labile and reactive for their age, and distracted. However, the direction of causality can be complex, as the literature notes that psychosocial factors can contribute to the etiology of UNDD (Bale, Baram, Brown, Goldstein, Insel, McCarthy, Nemeroff, et al, 2010).

Treatment of Unspecified Neurodevelopmental Disorder

The DSM-5 does not specify treatment for UNDD (American Psychiatric Association, 2013). Treatment will be dictated by diagnostic clarification, though there are overlapping treatment consideration across the spectrum of NDD/UNDD. The amygdala is noted as a common target for pharmacological interventions, given the commonality of amygdalary involvement in NDD Spectrum disorders (Schumann, Bauman, and Amaral, 2011). It could be postulated that behavioral interventions using CBT (Cognitive Behavioral Therapy) could also be beneficial by modulating anxiety in social situations. Family therapy may be indicated as the diagnostic picture clarifies. The long-term stressors associated with caring for a child with NDD/UNDD can strain a marriage or sibling relationships. The parents and siblings can also learn how to best support the NDD/UNDD child. Family therapy may also reveal conflicts and stressors that have led to a clinical presentation misinterpreted as UNDD.

Comorbidity of Unspecified Neurodevelopmental Disorder

Comorbidity is especially prevalent with NDD (McCary, Grefer, Mounts, Robinson, Tonnsen, & Roberts, 2012). There is also evidence that NDD has a common genetic causality (Elsevier Ltd., 2013). It is essential that there is accurate diagnosis of disorders in the NDD spectrum, as early diagnosis and intervention produce better long-term outcomes (McCary, Grefer, Mounts, Robinson, Tonnsen, & Roberts, 2012). A comorbid condition can be confused with the actual differential diagnosis listed above (See Differential Diagnosis). There are multiple conditions in the NDD spectrum, with high rates of co-morbidity due to their related etiology. The DSM-5 notes that the rate of co-morbidity in persons with Intellectual Disability is four to five times higher than in the general population (American Psychiatric Association, 2013).

Prognosis of Unspecified Neurodevelopmental Disorder

The Prognosis of UNDD will vary until there is diagnostic clarity. The prognosis for a child with AD/HD will be more favorable than one with an Intellectual Disability. It could be speculated that a prognostic factor in UNDD is the quality of maternal/familial support, given the established influence of environmental factors in NDD (Bale, Baram, Brown, Goldstein, Insel, McCarthy, Nemeroff, et al, 2010)

References

American Psychiatric Association. (2013). Diagnostic and Statistical Manual of Mental Disorders. (5th Edition). Washington, DC.

Bale, T.L., Baram, T.Z., Brown, A.S., Goldstein, J.M., Insel, T.R., McCarthy, M.M., Nemeroff, C.B., Reyes, T.M., Simerly, R.B., Susser, E.S., and Nestler, E.J. (2010). Early Life Programming and neurodevelopmental disorders. Biological Psychiatry. 68(4): 314–319. doi:10.1016/j.biopsych.2010.05.028. PMCID: PMC3168778. NIHMSID: NIHMS321195

Elsevier Ltd. (2013). A shifting view of Neurodevelopmental Disability. The Lancet Neurology. 12, 4. 323. doi: 10.1016/S1474-4422(13)70063-2

Krakowiak, P., Walker, C.K., Bremer, A.A., Baker, A.S., Ozonoff, S., Hansen, R.L., and Hertz-Picciotto, I. (2012). Maternal Metabolic Conditions and Risk for Autism and Other Neurodevelopmental Disorders. Pediatrics.129 (5). 1121 -1128. doi: 10.1542/peds.2011-2583.

Landgren, M., Svensson, L., Strömland, K., and Grönlund, M.A. (2010). Prenatal Alcohol Exposure and Neurodevelopmental Disorders in Children Adopted From Eastern Europe. Pediatrics. 125 (5). 1178 -1185. doi: 10.1542/peds.2009-0712.

McCary, L.M., Grefer, M. Mounts, M., Robinson, A., Tonnsen, B., and Roberts, J. (2012).

The importance of differential diagnosis in neurodevelopmental disorders: Implications for IDEIA. The School Psychologist. Retrieved October 18, 2014, from http://www.apadivisions.org/division-16/publications/newsletters/school-psychologist/2012/04/neurodevelopmental-disorder-implications.aspx

Schumann, C.M., Bauman, M.D., and Amaral, D.G. (2011). Abnormal structure or function of the amygdala is a common component of neurodevelopmental disorders. Neuropsychologia. 49, (4): 749-755.

Zoghbi, H.Y., and Bear, M.F. (2012). Synaptic Dysfunction in Neurodevelopmental Disorders Associated with Autism and Intellectual Disabilities. Cold Spring Harbor Perspectives in Biology. doi: 10.1101/cshperspect.a009886 .

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